Packaging method and apparatus

ABSTRACT

A packaging machine and method for automatic or semi-automatic operation with a bag sealing station provided laterally rearwardly of a bag loading station. A web of interconnected heat-sealable bags are successively fed to the bag loading station. The loaded bag is moved rearwardly to the sealing station and is there clamped against a heater bar by a movable sealing bar. Automatic bag packaging is accomplished by providing a pivotally mounted sealing and detaching assembly which tears the loaded bag from the web during the sealing operation. Heat sealing is accomplished concurrently with separation of the loaded bag from the web. Teeth penetrate the web above the seal to prevent separation of the web at the seal and to assure separation along a preformed line of weakness above the seal. As the sealing bar is released from its clamping position, the web is advanced to move a successive bag into the bag loading position. Semi-automatic bag packaging is accomplished by manually tearing the loaded bag from the web and manually inserting the bag in the sealing station. In semi-automatic operation the web is fed to advance a successive bag to the bag loading position concurrently with the sealing of a bag in the sealing position.

United States Patent 1 1 Lerner 1 May 13, 1975 1 PACKAGING METHOD ANDAPPARATUS [75] Inventor: Bernard Lerner, Hudson, Ohio [73] Assignee:Automated Packaging Systems, Inc.,

Twinsburg, Ohio 22 Filed: Dec. 6, 1973 21 Appl. No.: 422,281

Related U.S. Application Data [62] Division of Ser. No. 139,453, May 3,1971, Pat. No.

[52] U.S. Cl. 53/29; 53/37; 53/187 [51] Int. Cl. B65B 43/12; B65B 43/36;B65B 51/00 [58] Field of Search 53/29, 33, 35, 37, 39, 53/187, 182, 189,182 M, 372, 373, 385

[56] References Cited UNITED STATES PATENTS 3,050,916 8/1962 Gausman eta1. 53/182 M 3,195,290 7/1965 Thompson 53/182 3,209,513 10/1965Cochrane... l 53/182 3,234,069 2/1966 Saas 53/182 M UX 3,367,087 2/1968J'zirund .1 53/385 X 3,420,034 1/1969 Saraisky et al.. 53/372 X3,448,555 6/1969 Shabram 53/29 3,471,990 10/1969 Bonuchi et al.. 53/372X 3,477,196 11/1969 Lerner 53/29 X Primary Examiner-Travis S. McGeheeAssistant Examiner-Horace M, Culver Attorney, Agent, or Firm-Watts,Hoffmann, Fisher & Heinke [57] ABSTRACT A packaging machine and methodfor automatic or semi-automatic operation with a bag sealing stationprovided laterally rearwardly of a bag loading station. A web ofinterconnected heat-scalable bags are successively fed to the bagloading station. The loaded bag is moved rearwardly to the sealingstation and is there clamped against a heater bar by a movable sealingbar.

Automatic bag packaging is accomplished by providing a pivotally mountedsealing and detaching assembly which tears the loaded bag from the webduring the sealing operation. Heat sealing is accomplished concurrentlywith separation of the loaded bag from the web. Teeth penetrate the webabove the seal to prevent separation of the web at the seal and toassure separation along a preformed line of weakness above the seal. Asthe sealing bar is released from its clamping position, the Web isadvanced to move a successive bag into the bag loading position.

Semi-automatic bag packaging is accomplished by manually tearing theloaded bag from the web and manually inserting the bag in the sealingstation. In semi-automatic operation the web is fed to advance asuccessive bag to the bag loading position concurrently with the sealingof a bag in the sealing position.

4 Claims, 9 Drawing Figures PAIENIEM 1 3W5 3 882,656

sum 10? 6 PATENTEU HAY I 3 M5 SHEE] 2 [JP I PACKAGING METHOD ANDAPPARATUS This is a division, of application Ser. No. 139,453, filed May3, 1971 and now Pat. No. 3,815,318.

CROSS REFERENCE TO RELATED PATENTS Flexible Container Strips, US. Pat.No. 3,254,828

I issued June 7, 1966 to Hershey Lerner. This patent will BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention relates topackaging and more particularly to a novel and improved machine forpackaging products in bags supplied in a web of interconnected bags.

2. The Prior Art Each of the referenced patents describes theutilization of a plastic web composed of a chain of interconnected bags.The bags are each open on one face while the other face of each bag isconnected to a contiguous bag along a line of weakness.

A simple mechanism for using a web of bags in packaging is described inthe Article Patent. A coiled web is positioned on a mandrel in a carton.A blower is coupled to the carton to provide a positive pressure withinthe carton. The bags are fed, closed-end first, through a slot in thecarton. As the bags emerge from the carton they are inflated by a flowof air emitted from the slot due to the positive pressure in the carton.A product is inserted in the inflated bag. The operator then moves theweb until the next bag emerges from the box and inflates, and alsoseparates the loaded bag for a sealing operation.

In the Machine Patent, a machine is described and claimed whichdispenses the bags, seals them and then severs them in sequential,automatic operations. In addition, the machine is adapted to beconnected to automatic counting and conveying equipment so that theproducts being packaged are all automatically measured and deposited inthe bags as the bags are fed to a load station. The Machine Patent alsoprovides a means for providing an interrupted heat seal line wherebyheavily loaded bags are not so weakened during the heat sealingoperation that they tear along the sealing line.

These two described systems for dispensing and loading bags, representrespectively a relatively simple, but slow, and a relatively complex,but fast, system for dis pensing, loading and sealing bags. Theoptimized system for any given packager depends on a number of variablessuch as the size and nature of the products being packaged, the numberof packages of any given product or group of products required, and thetotal number of packages, that is the total packaging rate, of thepackager.

In the past, the most commonly-used system for dispensing separating andsealing packages has been basically manual. A machine similar inappearance to that shown in the Machine Patent has been the mostcommonly used. With this commercially-successful arrangement, a web ofbags is mounted on a mandrel within a housing. The web is fed through anexit slot near the top of the housing and then downwardly until an openbag is at a load station near the top of the machine and near the exitslot.

In use, the operator deposits the product to be packaged in the open bagat the load station. The operator then grasps the loaded bag, pulling itdownwardly until the next bag is at the load station. The loaded bag isthen manually severed and the open end is inserted between the jaws of aheat sealer provided near the base of the housing. The jaws are thenactuated to close and effect a sealing of the bag. After a predeterminedtime interval, when a seal has been effected, the jaws will open,allowing the bag to drop in a box or other receptacle beneath themachine.

With the described method of operation, the loading, feeding, severing,and sealing steps are all sequential. Except to the extent that askilled operator may in part cause the feeding and severing steps tooverlap. The steps are not only performed sequentially, but the steps ofone cycle must be fully completed before another cycle begins. Inaddition, the system is relatively fatiguing in that the operator startsabove the machine picking up the parts to be placed in the bag, loadsthe bag, lowers it through the feeding, severing and sealing steps untilhis arms are at the base of the machine and then repeats. Thus, arelatively considerable amount of manual movement is required with eachcycle.

With the device of the Machine Patent there is a limitation as to thelength of a bag which can be handled in that sealing and severing areperformed at stations below the load station and along a path of webtravel. In addition, while performing the operations fully automaticallyand quite satisfactorily, there is a complexity in the system which isnot required for many purposes. Namely, there is a unique mechanism forbringing the faces of the bag into full registry. With small andrelatively light products, and certain other kinds of products,misregistration of the bag faces is not a serious problem. Moreover,while the described automatic machine is quite satisfactory for manyapplications, the machine does not afford flexibility of semi-automaticoperation. Neither does it permit the feeding of the web until all stepsof a cycle have been fully completed.

THE MACHINE OF THIS INVENTION With the machine of this invention; onemay, by simply changing the orientation of the sealer, provide eitherautomatic or semi-automatic operation. In the semi-automatic mode, thesealer is positioned behind a vertical path of web travel with jawspositioned to move relatively along a path paralleling the web path oftravel. After a bag has been loaded, the operator severs the bag andinserts the open end between the jaws of the heat sealer. The faces ofthe bag may be manually brought into registration.

A foot pedal is then actuated to cause the jaws to close.Simultaneously, a signal is sent to a web feed mechanism, such as thatdescribed in the Machine Patent, which feeds the web until a sensingmechanism detects a registered line of weakness in the web. Thus, thebag to be fed is being fed along its path in front of the bag beingsealed concurrently with the sealing operation.

When the sealing operation is completed the jaws of the sealer will opendropping the bag irrespective of the extent to which the succeedingcycle has progressed. Conversely, the web will feed until the next bagis in the load position and then stop for automatic or manual partsloading, all of which proceeds without regard to the preceding cycle andthe stage of the sealing operation.

In the automatic mode of the machine of the present invention, thesealing jaws are positioned to recipro cate horizontally. After the jawshave closed they are pivoted about a pivot point at one end of the jawswhich provides a horizontal pivot axis to sever the loaded bagconcurrently with the sealing. The jaws also pull the bag somewhatrearwardly of the path of web travel so that, once the severing has beencompleted, the feed cycle of a subsequent bag can commence prior to thetime when the sealing cycle is fully completed. So long as thesuccessive web fed has not been too ex tensive by the time thesealing-jaws open, the bag being 7 fed will drop between the jaws whenthey open.

At first blush, it would seem that severing and sealing concurrentlywould be an impossibility because one would anticipate a bag would severalong the seal line. One of the outstanding features of the presentinvention resides in the mechanism provided to prevent such severing.This mechanism includes a toothed knife which is above and heatinsulated from a heater bar which effects seals. A resilient pad, whichis on one of the jaws of the sealer, coacts with both the sealer. barand the knife.

After the jaws of the heat sealer are closed and the sealing operationhas commenced, as indicated above, one end of the sealer is moveddownwardly about a pivot axis near the other end. This downward movementis sharp and rapid to effect a separation of the bag being sealed fromthe succeeding bag in the web aiong a preformed line of seakness, suchas a row of perforations, delineating the ends of the two bags.

Where it is desirable to provide a chain of interconnected loaded andsealed containers, the tearing-off action of the automatic machine maybe set to function only at the completion of a pre-set number of sealingcycles. By such an arrangement, chains of any number of interconnectedloaded containers may be produced automatically.

In the semi-automatic mode of operation, the portions of a bag beingsealed are disposed essentially horizontally so that the bag hangs overparts of the lower jaw of the machine and other parts of the machine.With the bag so hanging over parts of the machine, the friction of thebag and the machine takes some of the load on the package so that thefull load or weight of the product being packaged is not imposed on theline along which a seal is being formed.

With the automatic version of the machine, however, the bag ishangingvertically from the seal and one would anticipate that the weightof the product, especially if a heavier product is being packaged, mightcause a bag separation along the heat seal line. This tendency ismitigated by the sharp, rapid downward movement of the heat sealer asthe bag is separated. Thus, by moving the bag down quickly, the effectis to reduce the force imposed by the weight of the product beingpackaged on the bag along the seal line. Where heavily loaded bags arebeing sealed, the interrupted heat seal method taught by the MachinePatent may also be used to assure that the bags do not sever along theseal line.

After the sealing operation has been completed, the.

jaws open and a stripper mechanism strips the sealed bag from the knife.The stripper mechanism also serves if the bag is V to strip the sealedbag from the sealer bar tending to stick to the sealer bar. I

The heater. .bar and kniferare positioned rearwardly of the path of bagtravel and of the loadstation. That is they are positioned closer to theframeof the machine than is the bag loading station. During the bagloading portion of a cycle, the coacting pad is in the heat sealer.

In accordance with another feature of the present invention the heaterbar and knife bar are disposed in 9 wardly of a slotted guard bracket.The slotted guard bracket serves both as a safety device and tofacilitate stripping of sealed containers from the heater bar and knifebar. With the heater bar and the knife bar disposed inwardly of theguard bracket, the possibility of accidentally contacting either ofthese bars is minimized. Moreover, since the web is caused to form agenerally Ushaped configuration upon insertion through the slotted guardbracket during sealing, the weight of a loaded bag will serve to' pullthe'sealed bag I away from the heater bar and knife bar at the compleftion of the sealing operation when the sealing bar pressure is released.

The sealing bar is air actuated. Should the operator; I accidentallyinsert his hand between the sealingbarand" I the guard bracket during.sealing, the air actu'ationis i f sufficiently weak to prevent injury.Moreover,-the "resil-.

ient pad carried by the sealing bar also serves to prevent such injury.I

From the preceeding discussion it willbe seen that witheither theautomatic or semi-automaticversion of this machine, there is aheatsealing station spaced latere I ally and rearwardly from thepath oftravel'of the bag and from the loading I station. Thus, a loaded 5 bagis moved rearwardly from the path of travel as the sealing step of acycle is commenceda vice versa, if the optimum conditions for agiven,pack-' ager change. I

Accordingly, it is the principal object of the pr e sent invention toprovide improved methods. and apparatus for packaging heat-sealablecontainers.

Other objects and a fuller understandingof the invention may be had byreferring to the following descrip tion and claims taken in conjunctionwith the'accornpanying drawings.

BRIEF DESCRIPTION 0F. THE DRAWINGS FIG. 1 is a top plan viewof anautomatic packaging machineconstructed in accordance with thepresentinvention;

laterally] I FIG. 2 is a sectional elevational view as seen from theplane indicated by the line 2-2 in FIG. 1;

FIG. 3 is an enlarged sectional elevational view of a portion of themachine shown in FIG. 2;

FIG. 4 is a sectional elevational view as seen from the plane indicatedby the line 44 in FIG. 2.

FIG. 5 is a schematic illustration of the automatic packaging machinewith the lower feed roll moved away from the upper feed roll tofacilitate threading of the web of interconnected bags between the feedrolls;

FIG. 6 is a schematic illustration of a bag being loaded in the loadingposition;

FIG. 7 is a schematic illustration of the container being moved to thesealing station at the beginning of the sealing operation;

FIG. 8 is a schematic illustration showing the pivotal movement of thesealing and detaching assembly during the sealing operation; and,

FIG. 9 is a sectional elevational view showing the packaging machine ofthe present invention arranged for semi-automatic operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, apackaging machine is a shown generally at 10. The packaging machine 10includes a supporting and protective outer cabinet 11. A web 12 ofinterconnected plastic bags is fed vertically upwardly from a storageregion (not shown) formed in the lower portion of the cabinet 11.

The web 12 is reeved over a first idler roller 13. From the idler roller13, the web 12 extends substantially horizontally and is reeved around asecond idler roller 14. From the idler roller 14, the web is directedupwardly by a guide bar 15 toward a pair of feed rolls 16, 17.

The upper and lower feed rolls 16, 17 as best seen in FIGS. 1 and 4,have a series of axially spaced enlarged cylindrical portions 18, 19respectively. Each of the enlarged portions 18 is in engagement with anenlarged portion 19. Portions 20, 21 of reduced diameter are between thecylindrical portions 18, 19 respectively.

A drive motor 26 is mounted by means of a bracket 27 within the cabinet11. Output shaft 28 of the motor 26 is provided with a drive pulley 29.A drive belt 30 is reeved around the drive pulley 29 and around a drivenpulley 31. The driven pulley 31 is secured to the upper feed roll 16. Bythis arrangement, the motor 26 is operative to effect the feeding of theweb 12 between the feed rolls l6, 17.

The upper feed roll 16 is journaled by a pair of bearings 22, 23. Thebearings 22, 23 are carried by brackets 24, 25 which are secured to thecabinet 11.

The lower feed roll 17 is journaled by a pair of bearings 36, 37. Thebearings 36, 37 are supported by a pair of brackets 38, 39. The brackets38, 39 as best seen in FIG. 1, comprise the outer ends of a pair of arms40, 41. The arms 40, 41 extend rearwardly from the region of the feedrolls 16, 17 and are pivotally mounted from the cabinet 11 by pivotalconnections 42,43.

The forward ends of the arms 40, 41 are supported by means of threadedlock bolts 44, 45. The lock bolts 44, 45 extend through apertures formedin the brackets 38, 39 and into the threaded apertures formed in thebrackets 24, 25. The lock bolts 44, 45 are provided with knurled heads46, 47 to facilitate their manual rotation.

Since the lower feed roll 17 is pivotally supported by means of the arms40, 41, it may be pivoted downwardly as is schematically shown in FIG. 5to facilitate the initial feeding of the web 12 between the feed rolls16, 17. With the lower feed roll 17 pivoted downwardly, the web 12 maybe fed straight through the machine 10 from the first idler roller 13 tothe lower feed roll 17. The arms 40, 41 may then be pivoted upwardly toraise the lower feed roll 17 into its operative position with the web 12disposed between the feed rolls 16, 17.

From the feed rolls 16, 17 the web 12 is fed downwardly along asubstantially vertical path of travel to a loading station. indicatedgenerally by the numeral 50, FIGS. 2 and 3. A loading chute 51 isprovided for discharging parts 52 into a bag 53 positioned in theloading stationv In order to facilitate opening of the container 53 whenin the loading station, a blower indicated generally by the numeral 54is provided within the cabinet 11. A vertically extending duct 55connects with the blower output duct 56. The vertically extending ducts55 is disposed adjacent one side of the cabinet 11 and serves to ductair from the blower 54, which is disposed beneath the web 12, to theregion above the web 12. A horizontally extending duct 57 connects withthe vertically extending duct 55 and discharges air from the blower 54into the region above the web 12. Air is thereby caused to flow over theupper feed roll 16 and downwardly along the surface of the web 12, asindicated generally by the arrows 58. This air flow serves to open a bagwhen it is positioned in the loading station 50.

In accordance with the automatic version of this machine of the presentinvention, a sealing and detaching means is provided for simultaneouslysealing a loaded bag and for separating the loaded bag from the web 12while the bag is being sealed. To these ends, a substantially verticallyextending guard bracket 60 is provided rearwardly of the path of travelof the web 12 adjacent the loading station 50. A slot 61 is provided inthe guard bracket 60. A heater bar 62 is positioned within the region ofthe slot 61. A knife-bar 63 having a toothed edge 64 is positioned abovethe heater bar 62 to project into the slot 61.

The slotted guard bracket 60 serves a number of functions. First, itacts as a safety device to prevent injury to the fingers or hands of anoperator by shielding the heater bar and the knife bar from contact.Second, it facilitates stripping of sealed containers from the heaterbar and the sealer bar. Since the portion of the web being sealed mustassume a generally U-shaped configuration upon insertion through theslot 61, the weight of the loaded bag will tend to pull the bagoutwardly and away from the heater bar and sealer bar at the completionof the sealing operation.

A sealing bar 64 is provided for clamping the faces of the bag 53 intoengagement with one another with this inner face in engagement with boththe heater bar 62 and the knife bar 63. A resilient rubber pad 65 iscarried by the sealing bar 64 to perform this clamping function.

The sealing bar 64 is supported by a pair of support rods 66, 67. Thesupport rods 66, 67 are journaled by a transversely extending bar 68 andby a pair of apertured brackets 69, 70. A transversely extending framemember 71 rigidly connects the inward ends of the rods 66, 67. A firstactuator means in the form of a pneumatic cylinder 72 is connectedbetween the transversely extending bar 68 and the transversely extendingframe member 71. By this arrangement, the support rods 66, 67 may bemoved axially by the actuator 72 to move the sealing bar 64 toward andaway from the heating bar 62 and the knife bar 63. The actuator 72 inits extended position serves to clamp the rubber pad 65 of the sealingbar 64 in engagement with the heating bar 62 and the knife bar 63, andin its retracted position serves to move the sealing bar away from theheater bar and the knife bar.

When the sealing bar 64 is in its outwardly extended position, the web12 with its integrally formed container 53 extends between the supportrods 66, 67. The container 53 is then solely supported by its connectionto the web 12. When, however, the sealing bar 64 is moved to its inwardsealing position, the rubber pad 65 serves to clamp both sides of thecontainer 53 against the heater bar 62 and the knife bar 63. At thistime, the container is supported by this clamping action. The heater bar62 then serves to heat seal the container 53 while the toothed edge 64of the knife bar 63 punctures the web at intermediate positions acrossthe web surface above the region of the heat seal.

When relatively heavily loaded containers are being sealed, it isfrequently desirable to provide an interrupted seal whereby the web isnot weakened across its entire width during the formation of the heatseal. This may readily be accomplished by wrapping a thread around theresilient pad 65 to compress spaced por tions of the pad such that no.seal will be effected in these regions.

In order to prevent the knife bar 63 from becoming heated by the heaterbar 62, a finned heat dissipator 73 is provided in contact with theupper surface of the knife bar 63. The heat dissipator 73 has a largefinned surface area for heat dissipation.

Inaccordance with another aspect of the present invention, as soon asthe sealing bar 64 has movedtto the sealing position, the sealing anddetaching assembly pivots downwardly, as is shown in phantom in FIG. 4to separate the bag 53 which is being sealed from the web 12. Ascissors-like tearing off action is thereby provided, as is furtherillustrated in FIG. 8. The separation is along a preformed line ofweakness in the web such as a row of perforations. The coaction of theknife 63 and the pad 65 assure that the separation is along thispreformed line of weakness rather than along the heat softened portionsof the bag present in the areas where sealing is being effected.

The sealing and detaching means therefore comprises a pivotally mountedassembly. This assembly is nect at their front ends with a transverselyextending frame member 82. By this arrangement, a rigid frame is formedcomprising the elements 68, 80, 81., 82 and this frame is pivotallymounted about the shaft 75. This frame serves to support the heater bar62, the knife bar 63, and the sealing bar 64, and the actuator 72 formoving the sealing bar.

A second actuator 85 is provided formovingthe scaling and detachingassembly about the pivot shaft 75., The second actuator connects at oneend with the cabinet ll, as is best seen in FIG. 4, at the otherzendwith a bracket 86. The bracket 86, in turn, connects" withthe sidebar811.

A stripper bar 96, as best seen in FIGS. 2 and 3, is pivotally mountedabout an axis)! from the guard,

bracket 60. A spring 92 biases the stripper bar against the frontsurface of the guard bracket 60. A magnet (not shown) carried by thesealing bar64 serves to snap the stripper bar outwardly .when thesealing bar 645 8 moves outwardly from its fullyinward position. By thisi i arrangement, the stripper bar serves to disengage x sealedcontainers from the heater bar and knife bar.

The operation of the packaging machine 10 may best i i be described withreference to the schematic FIGS. L5 J 6, 7, and 8. As has beenpreviously explained, the web 12 is initially fed over the first idlerrollerl3 and'be tween the feed rolls 16, 17 while the lowerfeed roll 17Ris in its lowered position, asillustrated in FIG.5."LThe lower feed rollsupport assembly is then moved to as upper position wherein the feedrolls l6, 17 are in. en-

gagement withthe web 12.

After the bag 53 is advanced to the loading position and opened asillustrated in FIG. 6, parts 52 aredischarged through the loading chute51 into the open bag 53. The sealing bar 64 is then drawn inwardly asshown in FIG. 7 to clamp both sides of the container 53 into engagementwith the heater bar 62 andthe knife bar 63. As soon as the rubber pad 65carried by the heater 7 I bar 64 has clamped the container against theheating I bar and the knife bar, the second actuator extends f to pivotthetsealing and detaching assembly about the.

shaft 75, as illustrated in FIG. 8."

During the scissors-like tearing action that isim parted by the pivotalmovement of the sealingand detaching assembly, several things occur.First, the movement of the sealing and detaching assembly is,sufficiently rapid to substantially withdraw the weightof the contentsof the container 53 from the region ofthe heat sea]. This action therebyremoves a substantial portion webratherthanalong the line of the heatseal.

With'the sealing and detaching assembly in the down C I wardly pivotedposition, the first actuator 72 is then rapidly retracted. This actiondraws the stripper bar outwardly to strip the sealed container 53awayfrom. I the region of the heater bar 62 and the knife bar 63., Thesealed container 53' is then free to drop ontoa suita Y able containeror conveyor which may be provided he neath the loading station 50.

The sealing and detaching assembly, with thesealin bar in its extendedposition, is then returned by the sec. ond actuator 85 to its sealingposition. At the same time an electrical control means (notshownloperates the motor 26 to advance the web 12. By thisarrangement,another container is brought to the loading position 50 g simultaneouslywith the return movement of thesealing and detaching assembly. Thecontainer is then loaded and the sealing operation automaticallyrepeated.

A semi-automatic version of the machine of this in vention is shown inFIG. 9. The semi-automatic version is substantially identical to theautomatic machine in many respects, and identical parts are indicatedwith the same reference numerals used previously. The semi-automaticversion principally differs from the automatic version in that thesealing unit is oriented vertically rather than horizontally, and theknife bar assembly is removed. Also, the cabinet of the machine isprovided with a forwardly extending guard portion to shield therepositioned sealing unit,

Referring to FIG. 9, a semi-automatic machine is shown generally at 98.The machine 98 includes an identical drive motor 26 and feed rolls 16,17 for advancing a web 12 of inter-connected bag-like containers as waspreviously described in conjunction with the automatic machine 10.

A loading position is established at 50. The web 12 of interconnectedcontainers feeds vertically downwardly from the feed rolls 16, 17 to theloading position where a container is opened by a stream of air adjacentthe loading chute 51. When the container is filled, the operator thentears the loaded container from the web along a preformed line ofweakness in the web between adjacent containers,

The cabinet 12 is provided with a forwardly extending guard portion 99.The guard portion 99 has a horizontally extending slot 101 formedtherethrough at a position behind the loading position 50. The slot 101defines a sealing station indicated generally by the numeral 100.

A heater bar 102 is provided adjacent the lower edge of the slot 101. Asealing bar 103 carrying a rubber pad 104 is provided for clamping bothsides of the open end of the container 53 against the heater bar 102. Apair of support rods 105 support the sealing bar 103 and are adapted tomove axially to move the sealing bar toward and away from the heater bar102.

A pneumatic actuator 106 is supported by a bracket 107 from the cabinet11. The actuator 106 connects with a transversely extending frame member108 which, in turn, connects with the support rods 105. By thisarrangement, the actuator 106 in its extended position serves toposition the sealing bar 103 away from the heater bar 102, and in itsretracted position serves to clamp the sealing bar 103 against theheater bar 102.

A foot operated control indicated generally by the numeral 110 isprovided in the lower region of the cabinet ll. The foot control 110 isoperative to control a pneumatic valve 111 and an electrical motorcontrol (not shown). When the foot control 110 is depressed, the valve111 is opened to admit pressurized fluid from a hose 112 to a hose 113which connects with the actuator 106. The actuator 106 is thereby causedto extend to clamp the loaded container 53 against the heater bar 102.When the actuator 110 is released, the valve 111 vents the hose 113 toatmosphere to release the pressurized fluid from the actuator 106.

The foot operated actuator 110 also includes an electrical switch means(not shown) which controls the operation of the drive motor 26. By thisarrangement, depression of the foot control 110 causes the feed rolls16, 17 to advance the web 12 to bring a new bag into the loadingposition concurrent with the operation of the sealing mechanism. In thepreferred embodiment of the invention, the web 12 is caused to commenceto advance simultaneously with the movement of the sealing bar 103 fromits clamping position.

Although the invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

1. A method of packaging comprising the steps of:

a. providing structure defining a loading station;

b. feeding packaging web along a feed path to the loading station;

c. registering a container formed on the web with the loading station;and

(1. while said container is at the loading station and without movingsaid container into registry with another station:

i. loading said container;

ii. closing said loaded container;

iii. gripping a portion of said closed loaded container in such fashionas will effectively isolate an adjacent portion of said container fromstress producing forces imposed on another portion of said container;and,

iv, while said container is so gripped, initiating the performance of anoperation on said container which will impose stress producing forces onsaid another portions, whereby said adjacent portion remains effectivelyisolated from said forces.

2. A packaging apparatus comprising:

a. means establishing a path of travel for a packaging web to a loadingstation for positioning a container formed on the web in registry withthe loading station;

b. closure means operative while said container is positioned at saidloading station and without moving said container once it has beenloaded and to grip a portion of said closed loaded container in suchfashion as will effectively isolate an adjacent portion of saidcontainer from stress producing forces imposed on another portion ofsaid container; and

c. operating means operative while said container is gripped by saidclosure means and while said container remains at said loading stationto initiate the performance of an operation on said container which willimpose stress producing forces on said another portion, whereby saidadjacent portion remains effectively isolated from said forces.

3. A method of packaging comprising the steps of:

a. providing structure defining a loading station;

b. feeding a packaging web along a feed path to the loading station;

c. registering a container formed on the web with the loading station;and

d. while said container is at the loading station and without movingsaid container into registry with another station:

.i. loading said container;

ii. closing said loaded container;

iii. gripping a portion of said closed loaded container in such fashionas will effectively isolate an adjacent portion of said container fromstress producing forces imposed on another portion of said container;

v. while said container is so gripped, initiating the performance of asecond operation on said container which will impose stress producingforces on said another portion, whereby said adjacent portion remainseffectively isolated from said forces.

4. A packaging apparatus comprising:

a. means establishing a path of travel for a packaging web to a loadingstation for positioning a container formed on the web in registry withthe loading sta tion;

b. closure means operative while said container is positioned at saidloading station and without moving said container once it has been,loaded and to grip a portion of said closedloaded container insuchfashionas will effectively: isolate an adjacent portion of saidcontainer from stress producing forces said container remains at saidloading station to ini-- tiate, the performance of afirst operation onsaid container which will impose stress producing forces on said anotherportion, whereby said adjacent portion remains effectively isolated fromsaid forces; and i d. second operating'means operative while saidcontainer is gripped by said closuremeans and while said containerremains at the loading station to initiate theperformance of a secondoperation .on the adjacent portion ofsaid container. l l

1. A method of packaging comprising the steps of: a. providing structuredefining a loading station; b. feeding packaging web along a feed pathto the loading station; c. registering a container formed on the webwith the loading station; and d. while said container is at the loadingstation and without moving said container into registry with anotherstation: i. loading said container; ii. closing said loaded container;iii. gripping a portion of said closed loaded container in such fashionas will effectively isolate an adjacent portion of said container fromstress producing forces imposed on another portion of said container;and, iv. while said container is so gripped, initiating the performanceof an operation on said container which will impose stress producingforces on said another portions, whereby said adjacent portion remainseffectively isolated from said forces.
 2. A packaging apparatuscomprising: a. means establishing a path of travel for a packaging webto a loading station for positioning a container formed on the web inregistry with the loading station; b. closure means operative while saidcontainer is positioned at said loading station and without moving saidcontainer once it has been loaded and to grip a portion of said closedloaded container in such fashion as will effectively isolate an adjacentportion of said container from stress producing forces imposed onanother portion of said container; and c. operating means operativewhile said container is gripped by said closure means and while saidcontainer remains at said loading station to initiate the performance ofan operation on said container which will impose stress producing forceson said another portion, whereby said adjacent portion remainseffectively isolated from said forces.
 3. A method of packagingcomprising the steps of: a. providing structure defining a loadingstation; b. feeding a packaging web along a feed path to the loadingstation; c. registering a container formed on the web with the loadingstation; and d. while said container is at the loading station andwithout moving said container into registry with another station: i.loading said container; ii. closing said loaded container; iii. grippinga portion of said closed loaded container in such fashion as willeffectively isolate an adjacent portion of said container from stressproducing forces imposed on another portion of said container; iv. whilesaid container is so gripped, initiating the performance of a firstoperation on the adjacent portion of the container; and v. while saidcontainer is so gripped, initiating the performance of a secondoperation on said container which will impose stress producing forces oNsaid another portion, whereby said adjacent portion remains effectivelyisolated from said forces.
 4. A packaging apparatus comprising: a. meansestablishing a path of travel for a packaging web to a loading stationfor positioning a container formed on the web in registry with theloading station; b. closure means operative while said container ispositioned at said loading station and without moving said containeronce it has been loaded and to grip a portion of said closed loadedcontainer in such fashion as will effectively isolate an adjacentportion of said container from stress producing forces imposed onanother portion of said container; c. first operating means operativewhile said container is gripped by said closure means and while saidcontainer remains at said loading station to initiate the performance ofa first operation on said container which will impose stress producingforces on said another portion, whereby said adjacent portion remainseffectively isolated from said forces; and d. second operating meansoperative while said container is gripped by said closure means andwhile said container remains at the loading station to initiate theperformance of a second operation on the adjacent portion of saidcontainer.